The spinal column is a highly complex system of bones and connective tissues that provide support for the body and protect the delicate spinal cord and nerves. The spinal column includes a series of vertebral bodies stacked one atop the other, each vertebral body including an inner or central portion of relatively weak cancellous bone and an outer portion of relatively strong cortical bone. Situated between each vertebral body is an intervertebral disc that cushions and dampens compressive forces exerted upon the spinal column. A vertebral canal containing the spinal cord is located behind the vertebral bodies.
There are many types of spinal column disorders including scoliosis (abnormal lateral curvature of the spine), excess kyphosis (abnormal forward curvature of the spine), excess lordosis (abnormal backward curvature of the spine), spondylothesis (forward displacement of one vertebra over another), and other disorders caused by abnormalities, disease or trauma, such as ruptured or slipped discs, degenerative disc disease, fractured vertebra and the like. Patients that suffer from such conditions usually experience extreme and debilitating pain, as well as diminished nerve function.
To correct these spinal column disorders, a pair of rods is usually implanted into the spine using pedicle screw systems on the vertebral bodies. Cross-connectors that attach directly to spinal rods provide added rigidity to the spinal rod fixation constructs.
Currently, some cross-connectors come in fixed configurations which limit a surgeon's ability to determine the optimal spacing between a pair of spinal rods. Other cross-connectors are adjustable to adjust overall length, however they are only moveable in the lateral direction, which prevents the surgeon from placing the cross-connector in any area of a patient's body where anatomical features would impede the movement of the cross-connector.
Therefore, a need exists for improved cross-connectors.